The present invention relates in general to sealing means for axially confined annular grooves defined by a bushing and a shaft sleeve adapted to receive a rotating shaft, and has particular application to sealing means for rotating pump shafts.
In the past it has been the practice to employ packing or gaskets or O-rings for sealing rotating shafts of pumps confined within rotating bushing or sleeves. However, such packing and gaskets have prevented the pumping of liquids and fluids which are not compatable with the material comprising the packing or gaskets or O-rings. Thus, the inability of such pump assemblies to pump noxious and corrosive chemicals which attack and destroy the packing or gasket or O-ring seal has severely restricted their wide-spread application and adoption. Also, the space limitations and the dimensions of the annular groove between the rotating shaft, bushing and sleeve, have prevented the utilization of existing gland-type seals with the clamping devices thereon within the annular groove because such gland seals are bulky and require a large amount of space to perform the intended sealing function. Thus, the failure of such annular grooves to provide sufficient area for the gland seals, it has heretofore been impossible to utilize gland seals. Accordingly, such gland seals have been unacceptable in pumping assemblies for pumping corrosive chemicals.
Furthermore, the utilization of conventional O-rings to provide an effective seal between the bushing and the sleeve on the rotating shaft within a pumping assembly has proven undesirable because conventional O-rings take a compression set after repreated pressure loadings. Thus, conventional O-ring seals are not desirable because the O-ring seals are not sufficiently elastic nor are they resistive to solvents or chemicals. Consequently, the adoption of O-rings in pumping assemblies to pump corrosive chemicals has been severely restricted.